(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x-7\right)\left(x-6\right)$
$\left(x-7\right)\left(x+7\right)$
$\left(-x+5\right)\left(-4+x\right)$
$\left(-x+6\right)\left(4-x\right)$
$\left(-9+x\right)\left(x-3\right)$
$\left(5-x\right)\left(x-7\right)$
$\left(3-x\right)\left(1-x\right)$
$\left(-2+x\right)\left(9+x\right)$
$\left(3x+1\right)\left(5x+6\right)$
$\left(-4x+1\right)\left(-6x+5\right)$
$\left(-2x+1\right)\left(4-9x\right)$
$\left(3x+2\right)\left(1-x\right)$
$\left(-8+5x\right)\left(4x-1\right)$
$\left(3+5x\right)\left(4x-3\right)$
$\left(9+x\right)\left(1+2x\right)$
$\left(7-3x\right)\left(1+9x\right)$